OCAS, Gent, Belgium

Philippe Thibaux

Biography

Philippe Thibaux is responsible for non-standard testing at the research company OCAS. He has more than 25 years of experience in the field of steel, and has lead different projects in the field of structural integrity and fatigue of steel structures.

Conferences

Room

Date

Hour

Subject

Room 9

20-11-2025

1:30 pm – 2:00 pm

118 Results of the Jaco project: Effect of in-plane and out-of-plane loading on the cracking behaviour of tubular joints during large-scale tests

Conferences Details

118 Results of the Jaco project: Effect of in-plane and out-of-plane loading on the cracking behaviour of tubular joints during large-scale tests

Tubular joints are common in offshore structures, among others for foundations for wind energy convertors. In the JaCo project, large-scale fatigue tests were performed in-plane and out-of-plane on 45° joints. A consistent different cracking behaviour was observed between joints loaded in-plane compared to joints loaded out-of-plane. The in-plane loaded joints fail by cracking through the brace, after crack initiation at the crown heel and a limited crack growth in the width. The stiffness of the joint is also almost constant until failure. Cracks initiate at the saddle points in out-of-plane loaded joints and propagate along the weld toes, reaching a very large width. A significant decrease of the joint stiffness is observed at failure, allowing for a redistribution of the load during the test. Consequently, the cracking in out-of-plane is much more progressive than in-plane. Although the fatigue life in design rules is described by the same S-N curve for the heel and the saddle points, it was found that the fatigue life for in-plane loading is shorter than for out-of-plane loading, highlighting a limitation of the current hot spot method.

An event made by Cetim